| 1. |
- Beal, Jacob, et al.
(författare)
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Robust estimation of bacterial cell count from optical density
- 2020
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Ingår i: Communications Biology. - : Springer Science and Business Media LLC. - 2399-3642. ; 3:1
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Tidskriftsartikel (refereegranskat)abstract
- Optical density (OD) is widely used to estimate the density of cells in liquid culture, but cannot be compared between instruments without a standardized calibration protocol and is challenging to relate to actual cell count. We address this with an interlaboratory study comparing three simple, low-cost, and highly accessible OD calibration protocols across 244 laboratories, applied to eight strains of constitutive GFP-expressing E. coli. Based on our results, we recommend calibrating OD to estimated cell count using serial dilution of silica microspheres, which produces highly precise calibration (95.5% of residuals <1.2-fold), is easily assessed for quality control, also assesses instrument effective linear range, and can be combined with fluorescence calibration to obtain units of Molecules of Equivalent Fluorescein (MEFL) per cell, allowing direct comparison and data fusion with flow cytometry measurements: in our study, fluorescence per cell measurements showed only a 1.07-fold mean difference between plate reader and flow cytometry data.
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| 2. |
- dos Remedios, C. G., et al.
(författare)
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The Sydney Heart Bank : improving translational research while eliminating or reducing the use of animal models of human heart disease
- 2017
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Ingår i: Biophysical Reviews. - : Springer Nature. - 1867-2450 .- 1867-2469. ; 9:4, s. 431-441
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Tidskriftsartikel (refereegranskat)abstract
- The Sydney Heart Bank (SHB) is one of the largest human heart tissue banks in existence. Its mission is to provide high-quality human heart tissue for research into the molecular basis of human heart failure by working collaboratively with experts in this field. We argue that, by comparing tissues from failing human hearts with age-matched non-failing healthy donor hearts, the results will be more relevant than research using animal models, particularly if their physiology is very different from humans. Tissue from heart surgery must generally be used soon after collection or it significantly deteriorates. Freezing is an option but it raises concerns that freezing causes substantial damage at the cellular and molecular level. The SHB contains failing samples from heart transplant patients and others who provided informed consent for the use of their tissue for research. All samples are cryopreserved in liquid nitrogen within 40 min of their removal from the patient, and in less than 5–10 min in the case of coronary arteries and left ventricle samples. To date, the SHB has collected tissue from about 450 failing hearts (>15,000 samples) from patients with a wide range of etiologies as well as increasing numbers of cardiomyectomy samples from patients with hypertrophic cardiomyopathy. The Bank also has hearts from over 120 healthy organ donors whose hearts, for a variety of reasons (mainly tissue-type incompatibility with waiting heart transplant recipients), could not be used for transplantation. Donor hearts were collected by the St Vincent’s Hospital Heart and Lung transplantation team from local hospitals or within a 4-h jet flight from Sydney. They were flushed with chilled cardioplegic solution and transported to Sydney where they were quickly cryopreserved in small samples. Failing and/or donor samples have been used by more than 60 research teams around the world, and have resulted in more than 100 research papers. The tissues most commonly requested are from donor left ventricles, but right ventricles, atria, interventricular system, and coronary arteries vessels have also been reported. All tissues are stored for long-term use in liquid N or vapor (170–180 °C), and are shipped under nitrogen vapor to avoid degradation of sensitive molecules such as RNAs and giant proteins. We present evidence that the availability of these human heart samples has contributed to a reduction in the use of animal models of human heart failure.
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| 3. |
- Gu, Jian, et al.
(författare)
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Visualizing Material Processing via Photoexcitation-Controlled Organic-Phase Aggregation-Induced Emission
- 2021
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Ingår i: RESEARCH. - : American Association for the Advancement of Science (AAAS). - 2639-5274. ; 2021
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Tidskriftsartikel (refereegranskat)abstract
- Aggregation-induced emission (AIE) has been much employed for visualizing material aggregation and self-assembly. However, water is generally required for the preparation of the AIE aggregates, the operation of which limits numerous material processing behaviors. Employing hexathiobenzene-based small molecules, monopolymers, and block copolymers as different material prototypes, we herein achieve AIE in pure organic phases by applying a nonequilibrium strategy, photoexcitation-controlled aggregation. This strategy enabled a dynamic change of molecular conformation rather than chemical structure upon irradiation, leading to a continuous aggregation-dependent luminescent enhancement (up to similar to 200-fold increase of the luminescent quantum yield) in organic solvents. Accompanied by the materialization of the nonequilibrium strategy, photoconvertible self-assemblies with a steady-state characteristic can be achieved upon organic solvent processing. The visual monitoring with the luminescence change covered the whole solution-to-film transition, as well as the in situ photoprocessing of the solid-state materials.
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| 4. |
- Li, Zhongyu, et al.
(författare)
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Lighting up solid states using a rubber
- 2021
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Ingår i: Nature Communications. - : Springer Nature. - 2041-1723. ; 12:1
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Tidskriftsartikel (refereegranskat)abstract
- It is crucial and desirable to develop green and high-efficient strategies to regulate solid-state structures and their related material properties. However, relative to solution, it is more difficult to break and generate chemical bonds in solid states. In this work, a rubbing-induced photoluminescence on the solid states of ortho-pyridinil phenol family was achieved. This rubbing response relied on an accurately designed topochemical tautomerism, where a negative charge, exactly provided by the triboelectric effect of a rubber, can induce a proton transfer in a double H-bonded dimeric structure. This process instantaneously led to a bright-form tautomer that can be stabilized in the solid-state settings, leading to an up to over 450-fold increase of the fluorescent quantum yield of the materials. The property can be repeatedly used due to the reversibility of the tautomerism, enabling encrypted applications. Moreover, a further modification to the structure can be accomplished to achieve different properties, opening up more possibilities for the design of new-generation smart materials. Changes in molecular properties due to stimuli response are critically important for the development of new materials. However, most processes are slow or inefficient in the solid state. Here the authors demonstrate property switching in the solid state using a rubbing-induced tautomerism in multiple hydrogen-bonded donor-acceptor couples.
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| 5. |
- Liang, Jianxin, et al.
(författare)
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Mechanistic study of transcription factor Sox18 during heart development
- 2024
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Ingår i: General and Comparative Endocrinology. - : Elsevier BV. - 0016-6480 .- 1095-6840. ; 350
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Tidskriftsartikel (refereegranskat)abstract
- Heart development is a delicate and complex process regulated by coordination of various signaling pathways. In this study, we investigated the role of sox18 in heart development by modulating Wnt/β-Catenin signaling pathways. Our spatiotemporal expression analysis revealed that sox18 is mainly expressed in the heart, branchial arch, pharyngeal arch, spinal cord, and intersegmental vessels at the tailbud stage of Xenopus tropicalis embryo. Overexpression of sox18 in the X. tropicalis embryos causes heart edema, while loss-of-function of sox18 can change the signal of developmental heart marker gata4 at different stages, suggesting that sox18 plays an essential role in the development of the heart. Knockdown of SOX18 in human umbilical vein endothelial cells suggests a link between Sox18 and β-CATENIN, a key regulator of the Wnt signaling pathway. Sox18 negatively regulates islet1 and tbx3, the downstream factors of Wnt/β-Catenin signaling, during the linear heart tube formation and the heart looping stage. Taken together, our findings highlight the crucial role of Sox18 in the development of the heart via inhibiting Wnt/β-Catenin signaling.
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| 6. |
- Mitola, Joseph, et al.
(författare)
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Accelerating 5G QoE via public-private spectrum sharing
- 2014
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Ingår i: IEEE Communications Magazine. - : Institute of Electrical and Electronics Engineers Inc.. - 0163-6804 .- 1558-1896. ; 52:5, s. 77-85
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Tidskriftsartikel (refereegranskat)abstract
- Fifth generation wireless systems (5G) must achieve high user Quality of Experience (QoE) in order to compete for market share. Each candidate 5G wireless radio frequency (RF) band offers advantages such as longer range or higher data rate than 2G, 3G, and 4G, but no single band or air interface standard by itself fully achieves ubiquitous levels of QoE for the complete range of wireless access devices. Spectrum clearing cannot keep pace with user demand, so public-private spectrum sharing is emerging as an affordable, near-term method of increasing radio access network (RAN) capacities for content delivery. This paper presents a fresh look at QoE; spectrum scarcity; public uses that underutilize candidate 5G radio frequency (RF) spectrum; and emerging public-private radio interference management frameworks that enable near-term spectrum sharing, with positive consequences for 5G price, performance, and total user QoE.
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| 7. |
- Zhang, Man, et al.
(författare)
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Analysis of SiC MOSFETs Short-Circuit behavior in Half Bridge Configuration during Shoot-Through Event
- 2023
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Ingår i: 2023 IEEE Energy Conversion Congress and Exposition, ECCE 2023. - : Institute of Electrical and Electronics Engineers (IEEE). ; , s. 5350-5358
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Konferensbidrag (refereegranskat)abstract
- This paper investigates the short-circuit behavior of SiC MOSFETs in half bridge configuration during shoot-through event. The short-circuit peak current (ISCP) as well as the distribution of drain to source voltage (VDS) of half bridge configuration are analyzed under various mismatch operating condition. Further, the determinants on total amount and distribution of short-circuit energy (SC energy) are obtained. It is revealed that the device with the lowest short-circuit current carrying capacity determines the ISCP and the total SC energy of half bridge leg. Besides, the decrease of active switch common source inductance can mitigate the VDS and SC energy imbalance caused by load current. The conclusions are validated by experimental results.
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| 8. |
- Zhang, Man, et al.
(författare)
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Layout Design Principle for Optimization of Transient Current Distribution among Paralleled SiC MOSFETs in Multichip Modules
- 2023
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Ingår i: 2023 25th European Conference on Power Electronics and Applications, EPE 2023 ECCE Europe. - : Institute of Electrical and Electronics Engineers (IEEE).
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Konferensbidrag (refereegranskat)abstract
- This paper gives a layout design principle for multichip SiC MOSFET power modules taking the transient current distribution among paralleled dies into consideration. A few typical power module layouts are analyzed and modeled with parasitic layout parameters. With the analysis and comparison, a universal and practical design principle is proposed, which is to make the direction of parallel connections perpendicular to the direction of current flow. Applying this design principle mitigates the di/dt through the parasitic inductance between the source terminals of the paralleled dies. Furthermore, this approach avoids current coupling effects, which aggravate transient current imbalances. The design principle is verified with experimental results.
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| 9. |
- Zhang, Shang-Zhou, et al.
(författare)
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First-principles study of phase stability and elastic properties of binary Ti-xTM (TM = V,Cr,Nb,Mo) and ternary Ti-15TH-yAl alloys
- 2016
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Ingår i: Materials & design. - : Elsevier. - 0264-1275 .- 1873-4197. ; 110, s. 80-89
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Tidskriftsartikel (refereegranskat)abstract
- The phase stability and elastic property of binary Ti-chi TM (TM=V, Cr, Nb, Mo) and ternary Ti-15TH-yAl alloys are investigated systematically by using a first-principles method. The coherent potential approximation is employed to describe the random distribution of the alloying atoms in the alloys. We show that the transition metal (TM) elements V, Cr, Nb, Mo increase the elastic stability of the beta phase but decreases that of the a phase. The polycrystalline bulk modulus of the a phase increases with the concentration of the TM alloying elements whereas the Young's modulus and shear modulus are weakened. For the beta phase, all the polycrystalline elastic moduli hardens with the addition of the TM alloying elements. The influence of the simple metal (SM) element Al on the elastic properties is much weaker than the TM ones. The TM alloying elements increase the stability of the beta relative to the alpha and omega phases. Al stabilizes significantly the beta phase over the omega phase. Our calculations suggest that the d electron density dominates the elastic modulus but not the relative phase stability. The interaction between the TM and SM alloying elements in titanium alloys matters to the relative stability.
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